# Generate jpg files using line length (pixels) and orientation (degrees)

semeon.risom at gmail.com semeon.risom at gmail.com
Fri Jan 9 18:49:25 CET 2015

```On Thursday, 8 January 2015 20:54:38 UTC-6, Denis McMahon  wrote:
> On Thu, 08 Jan 2015 22:07:03 +0000, Denis McMahon wrote:
>
> > On Thu, 08 Jan 2015 09:09:18 -0800, semeon.risom wrote:
> >
> >> Simple question. I hope. .....
>
> To follow up, below is a solution to the problem you stated.
>
> #!/usr/bin/python
>
> import Image, ImageDraw, math
>
> def makeimg(length, orientation):
>     """
>     Make an image file of a black 4 pixel wide line of defined length
>     crossing and centered on a white background of 800 px square, save
>     as a png file identifying line length and orientation in the file
>     name.
>     param length - pixels, length of the line
>     param orientation - degrees, orientation ccw of the line from +ve x
>     axis
>     Files are saved in imgs subdir, this must already exist.
>     File name is image_lll_ooo.jpg
>     lll = length, ooo = orientation, both 0 padded to 3 digits
>     """
>
>     # check length is +ve and not greater than 800
>     if length < 0:
>         length = length * -1
>     if length > 800:
>         length = 800
>
>     # check orientation is positive in range 0 .. 179
>     while orientation < 0:
>         orientation = orientation + 360
>     if orientation > 179:
>         orientation = orientation % 180
>
>     radius = length / 2
>
>     # calculate xy coords in image space of line end points
>     x1 = int(400 + (radius * math.cos(orient)))
>     y1 = int(400 - (radius * math.sin(orient)))
>     x2 = int(400 + (-radius * math.cos(orient)))
>     y2 = int(400 - (-radius * math.sin(orient)))
>
>     # create an image
>     img = Image.new('RGB', (800,800), 'rgb(255, 255, 255)')
>     # create a draw interface
>     draw = ImageDraw.Draw(img)
>
>     # draw the line on the image
>     draw.line([(x1, y1), (x2, y2)], fill='rgb(0, 0, 0)', width=4)
>
>     # determine file name, save image file
>     fn = 'imgs/image_{:03d}_{:03d}.jpg'.format(length,orientation)
>     img.save(fn)
>
> # stepping through ranges of values
> for length in range(100, 601, 100):
>     for orientation in range(0, 171, 10):
>         makeimg(length, orientation)
>
> # using lists of values
> for length in [50, 150, 250, 350, 450, 550, 650]:
>     for orientation in [0, 15, 40, 45, 60, 75, 90, 105, 120, 135, 150,
> 165]:
>         makeimg(length, orientation)
>
>
>
>
> --
> Denis McMahon, denismfmcmahon at gmail.com

Thank you for the help btw. I think I'm close to a solution, but I'm having issue feeding the coordinates from my csv file into the formula.

This is the error I get:
Traceback (most recent call last):
File "C:\Users\Owner\Desktop\Stimuli Generation\Coordinates\Generate_w corr.py", line 68, in <module>
makeimg(length, orientation)
File "C:\Users\Owner\Desktop\Stimuli Generation\Coordinates\Generate_w corr.py", line 40, in makeimg
orientation = orientation % 180
TypeError: unsupported operand type(s) for %: 'list' and 'int'
>>>

and here's the code:

from PIL import Image, ImageDraw
from numpy import math

# import csv
import csv
f = open('C:\Users\Owner\DesktopStimuli Generation\Coordinates\file.csv', 'rb')
f.seek(0)
i = 0
a = []
b = []
for row in rdr:
a.append(row[0])
b.append(row[1])

def makeimg(length, orientation):
"""
Make an image file of a black 4 pixel wide line of defined length
crossing and centered on a white background of 800 px square, save
as a png file identifying line length and orientation in the file
name.
param length - pixels, length of the line
param orientation - degrees, orientation ccw of the line from +ve x
axis
Files are saved in imgs subdir, this must already exist.
File name is image_lll_ooo.jpg
lll = length, ooo = orientation, both 0 padded to 3 digits
"""

# check length is +ve and not greater than 800
if length < 0:
length = length * -1
if length > 800:
length = 800

# check orientation is positive in range 0 .. 179
while orientation < 0:
orientation = orientation + 360
if orientation > 179:
orientation = orientation % 180

# calculate xy coords in image space of line end points
x1 = int(400 + (radius * math.cos(orient)))
y1 = int(400 - (radius * math.sin(orient)))
x2 = int(400 + (-radius * math.cos(orient)))
y2 = int(400 - (-radius * math.sin(orient)))

# create an image
img = Image.new('RGB', (800,800), 'rgb(255, 255, 255)')
# create a draw interface
draw = ImageDraw.Draw(img)

# draw the line on the image
draw.line([(x1, y1), (x2, y2)], fill='rgb(0, 0, 0)', width=4)

# determine file name, save image file
fn = 'imgs/image_{:03d}_{:03d}.jpg'.format(length,orientation)
img.save(fn)

# using lists of values
for length in [a]:
for orientation in [b]:
makeimg(length, orientation)

```